Pump.



W. S. FRANKLN.

PUMP.

APPLIOATION FILED JAN. 1a, 1913.

Patented June 23, 191i iM/wooeo:

UNITED sTATEs PATENT oEEIoE.

WILLIAM S. FRANKLIN,

OF SOUTH BETHLEHEM, PENNSYLVANIA.

PUMP.

lSpecification of Letters Patent. L Patented; une 23, 1914. Application alec January 1s, 1913. serial No. 742,788.

j To all whom t may concern:

lBe it known that- I, WILLIAM S.' FRANK- LIN, of South Bethlehem, in the county of Northampton, and in the State of Pennsylvania, have invented a certain new and useful Improvement in Pumps, and do hereby declare that the following is a full, clear, and exact description thereof.

The object of the invention has been to provide a pump which, while capable of' the particular embodiment shown.

. In the illustrated embodiment, al pump has been provided by which ammonia vapor is condensed and pumped into a condensing pipe, the latter communicating through a suitable valve with a cooling pipe, where the vapor expands for refrigerating' purposes and is then returned to the pump.

The pump consists essentially of an elastic diaphragm preferably madev of sheet steel lying across a shallow lens-shaped .cavity between two strong plates and caused to vibrate up and down by alternately pumping a Huid against o'ne side, and allow- .ing the fluid to escape, thus causing the opposite side to admit and compress the vaporto be pumped.

In the illustrated embodiment has been provided an elastic diaphragm 1, preferably of sheet steel, which is preferably stretched across a shallow lens-shapedv cavity 2 between two heavy plates 3 and 4, respectively.

The joints 5 between the said plates are' preferably hermetically sealed and the plates are held together as by bolts 6 pass-A ing throuy ,h or engaging ears on Vthe plates 3 and 4. The sealing may be accomplished,

for example, by autogenous welding.

As illustrated, oil is pumped between the plate 4 and the diaphragm 1 to cause the latterl to vibrate and such oil enters the cavity between the two through fine perforations 7 in the plate 4, it being .delivered through a pipe 8 by a pump to be described. The pipe-8 preferably carries a collar or washer 9. The joint 10-between such collar and the plate 4 may be sealed by autogenous welding.

The'saidpump consists ofa cylinder 11 having a plunger' 12 which may be packed by a gland 13 and packing 14. The piston -1s operated by a. rod 15 between which and the piston is interposed a spring 16. In the presentinstance the piston is provided with a sleeve 17 which incloses the rod 15, but relative movement is permitted by the pin and slotconnection 18. The displacement volume of the plunger is made larger than the displacement volume of the diaphragm so that the diaphragm will be pushed against the plate 3 before the plunger reaches the bottom of its stroke, tinued motion of the pump rod- 15- is accommodated by the compression of the spring 16. This spring is under initial compres- -sion so that it does not yield until the oil pressure rises above a prescribed volume. An oil reservoir 19 is provlded around the Apump cylinder and communicates by. a check valve 20 with the pump cylinder. During the upstroke of the pump rod vthe following succession ofevents take place: (1) The compression spring 12 comes back to its initial position, then the diaphragm moves toward the plate 4 by the back pressure of the ammonia vapor, and then, if there has been any leakage of oil, the continued up movement of the plunger of the oil pump draws in a little oil through the valve 20 from the oil reservoir 19. The region between the diaphragm and the plate 3 is the ammonia pump chamber proper, into which the ammonia vapor enters from the cooling pipe 21, through a valve 22, and from which it is expelled through an outlet valve'23 into the condensing pipe 24. These valves are constructed so as to reduce the clearance space between the diaphragm and the plate 3 to a minimum, and each valve communicates with the region between the diaphragm and the plate 3 through a number of small holes 25 and 26, respectively, thus leaving the face of the plate 3 practically smooth, so that the diaphragm cannot be strained beyond its elastic limit, even though it be made very thin and be forced very strongly against the plate 3.

An order to give the valves the smallest and the con- 4 practically Smooth possible clearance and make them as simplev as possible, I have shown them in the drawings as gravity operated valves, and for this purpose have turned their pipes 21 and 24 vertically, and for simplicity have also made the diaphragm and the plates 3 and 4 vertical. It will be understood, however7 that the plates and diaphragm could be made horizontal.

It is highlydesirable in the operation of the pump that the oil be sure to fall to atmospheric pressure when the oil pump 1s stopped, and when such action takes place the diaphragm must sustain the full pressure of the ammonia vapor. But the diaphragm must be fairly thin to be operative, and to enable a thin diaphragm to sustain the full pressure of the ammonia vapor, the face of the plate 4 must be practically smooth, so that the diaphragm can fall back flat against it without being strainedanywhere beyond its elastic limit.v The introduction of the oil through the fine holes 7 meets these conditions. On the other hand, when the `diaphragm is forced against the plate 3 to compress the ammonia vapor, as such plate is and complete, it perfectly sustains the. disk, even though the latter be very thin and be forced completely against the said plate, so as to take up all clearance in the pump. This is because the valves 22 and 23 do not communicate directly with the pump, butonly through the fine perforations 25 and 26. Thus the disk is not strained beyond its elastic limit in-either direction. Q f

This case is a continuation of my previous application, Serial No. 679,049, led February 21, 1912, so far as the generic invention is concerned.

I claiml. In a pump, the combination with a pumping chamber and an inlet passage and an outlet passage'in communication therewith, of a resilient diaphragm secured at its periphery to the inner wall of said chamber v so that it lies normally substantially flat, the

form of the chamber and the position of the diaphragm being such that the diaphragm may be pressed on its working stroke snugly against the surface of the chamber substantially throughout the extent of both, whereby substantially all clearance within the chamber is avoided, and means forsubjecting the opposite side of the diaphragm to Huid pressure to produce its working stroke.

2. In a pump, the combination with a pumping chamber and an inlet passage and an outlet passage in communication therewith, of a metallic diaphragm secured at its periphery to the inner wall of said chamber so that it lies normally substantially fiat, the .form of the chamber and the position of the diaphragm being such that the diaphragm may be pressed on its working stroke snugly against the surface of the chamber substantially throughout the extent of both, whereby substantially all clearance within the chamber is avoided, and means for subjecting the opposite side of the dia. phragm to fluidI pressure to produce its working stroke.

3. In a pump, the combination with a pumping chamber and an inlet passage and an outlet passage in communication therewith, of a metallic diaphragm secured at its periphery tothe inner wall of said chamber so that it lies normally substantially flat, the form of the chamber and the position of the diaphragm being such that the diaphragmA may be pressed on its working stroke snugly against the surface of the chamber substantially throughout the extent of both, whereby substantially all clearance vwithin the chamber is avoided, and means for subjecting the opposite side of the diaphragm to fluid pressure to produce its working stroke, a portion -of said apparatus confining the fluid pumped by the said fluid pump being yielding. l v

4. A pump comprising a flexible metal sheet, plates between which said sheet isclamped, said plates being dished so that said sheet may substantially'l rest against them at the limits of its movement.

5. A refrigerant pump comprising a flexible metal sheet, plates between which said sheet is clamped, said plates being dished so that said sheet may substantially rest against them at the limits of its movement, delivery and intake pipesentering through one of said plates, and a fluid pump having a connection through the other of said plates.

6. A pump comprising a flexible diaphragm, plates between which said diaphragm is mounted, said plates having lensshaped cavities therein, which said diaphragm is adapted t0 lit at the limits of its movements, a fluid pump and perforations through one of saidplates by which said fluid may enter to reach said diaphragm.

In testimony that I claim the foregoing I have hereunto set my hand.

WILLIAM S. FRANKLIN.

Witnesses:

EDWIN J. PRINDLE, L. BRoDERI-CK'. 

